The GE Lighting FAQ (thanks, squidbot): http://www.gelighting.com/na/home_lighting/ask_us/faq_compact.htm#mercury http://www.gelighting.com/na/home_lighting/as

The GE Lighting FAQ (thanks, squidbot): http://www.gelighting.com/na/home_lighting/ask_us/faq_compact.htm#mercury http://www.gelighting.com/na/home_lighting/ask_us/faq_compac... says that GE's bulbs contain about 5mg of mercury apiece. The OSHA guidelines on mercury vapor: http://www.osha.gov/SLTC/healthguidelines/mercuryvapor/recognition.html http://www.osha.gov/SLTC/healthguidelines/mercuryvapor/recog... ... states the following: The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for mercury vapor is 0.1 milligram per cubic meter (mg/m(3)) of air as a ceiling limit. A worker's exposure to mercury vapor shall at no time exceed this ceiling level. The National Institute for Occupational Safety and Health (NIOSH) has established a recommended exposure limit (REL) for mercury vapor of 0.05 mg/m(3) as a TWA for up to a 10-hour workday and a 40-hour workweek. Now all we need to know is that a 12 foot by 12 foot by 8 foot bedroom is about 4 by 4 by 2.5 meters, which adds up to about 40 cubic meters. Break a mercury bulb in that room, disperse 100% of the mercury in the bulb throughout the room, assume the room is leakproof, and stay in the room breathing deeply for several minutes after the bulb breaks and you'll get exposed to 0.125 mg/m(3). This is about twice as high as the maximum amount that you should be breathing for 10 hours per day, 40 hours per week. But it is barely above the maximum legal exposure limit for workers. Now consider that your bedroom isn't airtight -- assuming your house is either properly ventilated or improperly insulated. ;) Not only will the mercury distribute itself through the house, but it will then leave the house, within a matter of an hour. Also, not all of the mercury is likely to leak; some of it will condense in the bulb. And all of this will only happen once per bulb failure. Conclusion: I'd find something more important to worry about. You probably don't have to look very far, because this risk is pretty low. If you just can't stop worrying without taking action, turn on a fan and open the windows for five minutes every time a bulb burns out. You'll still save plenty of energy. Second-order conclusion: Take a class on solving Fermi problems. ;)